An implement system of a typical excavator machine includes a linkage structure operated by hydraulic actuators to move a work implement. The implement system includes a boom that is pivotal relative to a machine chassis, a stick that is pivotal relative to the boom, and a work implement that is pivotal relative to the stick. Further, the machine chassis is rotatably mounted on an undercarriage or drive system of the excavator and adapted to swing about a vertical axis. The coordinated movements of the boom, the stick, the work implement and the chassis provide the overall movement of the implement system for achieving various digging operations or the like.
Most excavators utilize a right-hand control lever and a left-hand control lever to control movement of the machine chassis, the boom, the stick and the work implement. The control levers are provided in an operator cab and disposed on left and right sides of the operator's seat, respectively. The right-hand control lever controls the movement of the boom and the work implement. The left-hand control lever controls the movement of the stick and the machine chassis. Collectively or individually, the left and right control levers control the movement of the implement system while performing a digging or loading operation. However, this control system requires an operator to learn how to move the work implement by manipulating a rate of change and angular position of the boom, the stick, and the work implement.
U.S. Pat. No. 5,675,359 (referred to as '359 patent) discloses a joystick controller for utilizing omnidirectional pivoting manual displacement by an operator, to operate transducers for producing control signals. The joystick controller includes a mounting plate defining an opening and gimbal mounting means secured to the mounting plate for pivotally mounting a joystick shaft extending through the opening. The joystick shaft has an operator knob on one end, and a gauge plate on the other end. The gauge plate has a first straight edge and a second straight edge perpendicular thereto. First and second lever arms are pivotally mounted and biased against the first and second straight edges of the gauge plate. The '359 patent provides that displacement of the joystick knob causes displacement of the gauge plate and pivots the lever arms biased against the joystick knob.